Jean-Baptiste Bouillaud, Claude-François Lallemand, and the role of the frontal lobe: location and mislocation of language in the early 19th century

Henry Hun and his family: Three foundational stories in the history of nineteenth-century American neurology, Part I. Thomas Hun (1808-1896): Nineteenth-century patriarch, neurophilosopher, and proto-neurologist

Thomas Hun (1808-1896)-along with his sons Edward (1842-1880) and Henry (1854-1924)-were prime movers in establishing the clinical practice and academic discipline of neurology in the Hudson River Valley of New York in the ninteenth and early-twentieth centuries. This article outlines the life of the family's semi-aristocratic patriarch, beginning with Thomas's unusual educational background and his six-year post-graduate hiatus in Paris of the 1830s, where he came under the influence of P. C. A. Louis (1787-1872). It lays out his subsequent career as professor of the Institutes of Medicine and ultimately as dean of an American medical school that was not situated in a major metropolis. It also will demonstrate how Thomas Hun's career as a medical practitioner, academician, neurophilosopher, and "proto-neurologist" recapitulates the evolution of clinical and academic neurology in nineteenth-century America.

Streptavidin-Saporin: Converting Biotinylated Materials into Targeted Toxins

Streptavidin-Saporin can be considered a type of ‘secondary’ targeted toxin. The scientific community has taken advantage of this conjugate in clever and fruitful ways using many kinds of biotinylated targeting agents to send saporin into a cell selected for elimination. Saporin is a ribosome-inactivating protein that causes inhibition of protein synthesis and cell death when delivered inside a cell. Streptavidin-Saporin, mixed with biotinylated molecules to cell surface markers, results in powerful conjugates that are used both in vitro and in vivo for behavior and disease research. Streptavidin-Saporin harnesses the ‘Molecular Surgery’ capability of saporin, creating a modular arsenal of targeted toxins used in applications ranging from the screening of potential therapeutics to behavioral studies and animal models. The reagent has become a well-published and validated resource in academia and industry. The ease of use and diverse functionality of Streptavidin-Saporin continues to have a significant impact on the life science industry.

History of aphasia: A broad overview

This chapter gives a broad overview of the description and theorizing of a wide range of language disorders resulting from brain damage, commonly classified under the umbrella term "aphasia." It covers works written in Antiquity up to the 20th century. Moreover, it looks at disturbances in various language modalities such as speech, language comprehension, reading, writing, and sign language. In addition, also forms of the more recently discovered primary progressive aphasia are discussed. Finally, important developments in the history of assessment and rehabilitation of language disorders are described. To properly characterize disorders of language, these developments are discussed from the perspectives of neurology, psychology, and linguistics.

A Parisian spring: the debate on language localization at the Imperial Academy of Medicine, Paris, April 4-June 13, 1865

The localization of articulate language (speech) to the posterior third of the third left frontal convolution-Broca's area-did not occur to Broca as he reported the case of his first aphasic patient in 1861. Initially Broca localized articulate language to both frontal lobes, a position that he maintained for 4 years after publishing his first case. In the interval, the Academy of Medicine in Paris had received a copy of a paper authored in 1836 by Marc Dax, in which Dax claimed that the ability to speak resides within the left hemisphere alone. The Academy of Medicine convened in the spring of 1865 to adjudicate the issue. All of the distinguished speakers argued against Dax's contention by citing the prevailing paradigm, that bilaterally symmetrical organs, such as the eyes and ears, and the hemispheres of the brain, must perform the same function. The lone dissenting voice was that of Jules Baillarger, the discoverer of the laminar organization of the cerebral cortex, whose argument in favor of what he called "Dax's law" was so lucid that it carried the day. During his address to the Academy, Baillarger not only supported left-hemisphere dominance for speech, but for the first time described two forms of aphasia, fluent and nonfluent, now referred to as Wernicke's and Broca's aphasias, respectively, as well as the ability of aphasics to speak during emotional outbursts, to which we now refer as Baillarger-Jackson aphasia. It was 9 days after Baillarger's address that Broca, for the first time, unequivocally localized speech to the left frontal lobe.This paper is based on the author's reading of Dax's and Broca's original texts and of the texts read before the Academy of Medicine meeting held at the National Library of France between April 4, 1865, and June 13, 1865. From these primary sources it is concluded that the Academy of Medicine's debate was the last serious challenge to left-hemisphere dominance for speech and to the localization of articulate language to the left frontal lobe-and that Jules Baillarger played a pivotal role in what was a defining moment in neurobiology.

A brief history of cortical functional localization and its relevance to neurosurgery

Modern cortical mapping is a cornerstone for safe supratentorial glioma resection in eloquent brain and allows maximal resection with improved functional outcomes. The unlocking of brain functionality through close observation and eventually via cortical stimulation has a fascinating history and was made possible by contributions from early physician-philosophers and neurosurgery’s founding fathers. Without an understanding of brain function and functional localization, none of today’s modern cortical mapping would be possible.

Cerebral localization of higher functions: The period between Thomas Willis and Paul Broca

The age-old debates about the localization of the mind (higher functions) took a new course when Willis located a higher nervous function (memory) in the brain parenchyma, and supposedly, in the cerebral cortex. About two centuries later, Broca, founded on solid scientific reasoning, localized a circumscribed area of the 3^rd frontal circumvolution of the left hemisphere as the seat of articulate language, a higher function (speech - language domain). He (and Dax) also defined the functional asymmetry (specialization) of the hemispheres, with left dominance (for language). The period between the findings of these individuals was not quiescent, as numerous authors contributed with their theoretical and clinicopathological research toward creating a conducive scientific atmosphere for this accomplishment, and should be regarded as important. Further studies, in the decades that followed, revealed the localization of additional aspects of language and of other higher functions (cognitive domains).

Broca's Aphemia: The Tortuous Story of a Nonaphasic Nonparalytic Disorder of Speech

Broca coined the neologism "aphemia" to describe a syndrome consisting of a loss of the ability to speak without impairment of language and paralysis of the faciolingual territories in actions unrelated to speech, such as protruding the tongue or pursing the lips. Upon examining the brains of patients with aphemia, Broca concluded that the minimum possible lesion responsible for aphemia localized to the posterior left inferior frontal gyrus and lower portion of the middle frontal gyrus. A review of Broca's writings led us to conclude that (a) Broca localized speech, not language, to the left hemisphere, (b) Broca's aphemia is a form of apraxia, (c) Broca's aphemia is not, therefore, a terminological forerunner of aphasia, and (d) Broca was an outspoken equipotentialist concerning the cerebral localization of language. Broca's claim about the role of the left hemisphere in the organization of speech places him as the legitimate forebear of the two most outstanding achievements of Liepmann's work, namely, the concepts of apraxia and of a left hemisphere specialization for action.

Broca's faculté du langage articulé: Language or Praxis?

De Oliveira-Souza, Moll, and Tovar-Moll (this issue) historically reevaluate that Paul Broca's aphemia should be considered as a kind of apraxia rather than aphasia. I argue that such a claim is unwarranted, given the interpretation of the faculty of speech Broca derived from his predecessors, Jean-Baptiste Bouillaud and Franz Joseph Gall, and also with a view on the then generally held opinion that the terms aphémie and aphasie were synonyms. I will discuss evidence that patients such as Leborgne, producing only very few words or syllables, suffer from a global aphasia, affecting all modalities, despite Broca's statement that Leborgne's comprehension was intact. I also point to Broca's claim that the faculty of speech, located in the left anterior hemisphere, is independent from hand preference because it is an intellectual and not a motor function, and to his statement that the cerebral convolutions are not motor organs. I finally contend that, in order to determine whether a given language problem should be labeled as aphasia or apraxia, it is crucial to first be clear on the components of old and new models of language production.

The anatomical foundations of acquired reading disorders: a neuropsychological verification of the dual-route model of reading

In this study we investigated the neural correlates of acquired reading disorders through an anatomo-correlative procedure of the lesions of 59 focal brain damaged patients suffering from acquired surface, phonological, deep, undifferentiated dyslexia and pure alexia. Two reading tasks, one of words and nonwords and one of words with unpredictable stress position, were used for this study. We found that surface dyslexia was predominantly associated with left temporal lesions, while in phonological dyslexia the lesions overlapped in the left insula and the left inferior frontal gyrus (pars opercularis) and that pure alexia was associated with lesions in the left fusiform gyrus. A number of areas and white matter tracts, which seemed to involve processing along both the lexical and the sublexical routes, were identified for undifferentiated dyslexia. Two cases of deep dyslexia with relatively dissimilar anatomical correlates were studied, one compatible with Coltheart's right-hemisphere hypothesis (1980) whereas the other could be interpreted in the context of Morton and Patterson's (1980), multiply-damaged left-hemisphere hypothesis. In brief, the results of this study are only partially consistent with the current state of the art, and propose new and stimulating challenges; indeed, based on these results we suggest that different types of acquired dyslexia may ensue after different cortical damage, but white matter disconnection may play a crucial role in some cases.

Revisiting the contributions of Paul Broca to the study of aphasia

There are few iconic publications in the annals of clinical neuroscience that have had the impact of Paul Broca's 1861 paper that appeared in the Bulletin de la Société Anatomique Broca (Bulletin Society Anatomique, 6:330-357, 1861). It was, however, by no means his last word on the matter of language localization, specifically, or on the overarching principle of regional specialization of brain function. Thus we comment on English translations of two of his works: the original paper and another from 1865. Although the 1861 paper has received the most credit, his manuscript 4 years later and based on a much larger case series was the first to state based on empirical observation that the left frontal region was responsible for articulated speech. Moreover, his observations of aphasia recovery reported in this later work led to his own hypotheses on the importance of cerebral reorganization after injury and to the differences in reacquisition of adult language vis-à-vis the nature of initial language development that were verified a century later. He also proposed a method of language remediation whose efficacy was not established for another 100 years. Thus Broca's contributions to the contemporary study of aphasia reach far beyond his initial case presentation.

Chapter 36: history of aphasia: from brain to language

An historical overview is presented that focuses on the changes both in approach and topics with respect to language disturbances due to brain lesions. Early cases of language disorders were described without any theorizing about language or its relation to the brain. Also, three forms of speech disorder were distinguished: traulotes, psellotes and ischophonia, which are only marginally related to aphasia. In the 18th century some authors, in particular Gesner and Crichton, attempted to explain language disorders in terms of mental processes. The great debate on both the anatomical (Broca, Wernicke) and functional (Wernicke, Lichtheim) aspects of aphasia dominated late 19th century discussion of localization of function, leading to the development of what we now call the cognitive neurosciences. In this period, language processing was described in terms of a simple functional model of word recognition and production; linguistic principles played no role. At the beginning of the 20th century the discussion on language disorders waned due to a decrease of interest in the issue of localization; aphasia became primarily a clinical issue of how best to classify patients. In the second half of the 20th century, the field of aphasia developed rapidly due to studies performed at the Boston Aphasia Unit and, more importantly, to a change of orientation to linguistic notions of language structure, as introduced by Chomsky.

Chapter 40: history of neurology in France

The history of neurology in France is characterized by the very high degree of centralization in that country where "everything seems to happen in Paris," and yet the considerable degree of autonomous diversity in the evolution of some other medical schools such as Montpellier and Strasbourg. It could be argued that France saw the birth of clinical neurology as a separate discipline since Jean Martin Charcot at the Salpêtrière Hospital obtained a chair of diseases of the nervous system in 1892, a first in the history of the academic world. The chapter shows, however, that the work of Charcot was preceded by a long evolution in medical thinking, which culminated with the introduction of experimental medicine developed by Claude Bernard and François Magendie, and by the study of aphasia by Paul Broca and its localization of language in a specific area of the brain. Many of the great neurologists of France like Duchenne de Boulogne, Gilles de la Tourette, Joseph Babinski and Pierre Marie gravitated around Charcot while others like Charles-Edward Brown-Sequard and Jules Dejerine developed their talents independently. The history of Sainte-Anne Hospital further illustrates this independence. It also shows the relation between neurology and psychiatry with Henri Ey, Jean Delay and Pierre Deniker, who collaborated with Henri Laborit in the clinical development of chlorpromazine. Sainte Anne also saw the birth of modern neuropsychology with Henry Hécaen. Jean Talairach and his group developed human stereotaxic neurosurgery and a 3-dimensional brain atlas that is used around the world. The chapter also mentions institutions (the CNRS and INSERM) that have contributed to developments partially independently from medical schools. It concludes with a presentation of schools located outside of Paris that have played a significant role in the development of neurology. Six of the most important ones are described: Montpellier, Toulouse, Bordeaux, Strasbourg, Lyon, and Marseilles.